Method of assaying collagen fragments in body fluids, a test KT and means for carrying out the same

ABSTRACT

A method of assaying collagen fragments in body fluids, including bringing a sample of body fluid in contact with at least one immunological binding partner for the collagen fragments, said binding partner being immunoreactive with synthetic peptides, the sequences of which are essentially derived from collagen and containing potential sites for cross-linking. The immunological binding partners are incorporated, either as whole antibodies or as immunologically active fragments thereof, in an assay for quantitative determination of collagen fragments in the sample. In addition to being contacted with the immunological binding partner(s), the sample may be brought into direct contact with the corresponding synthetic peptide. The invention further comprises a test kit and specific means for carrying out the method. The structure of specific peptides is also described.

This is a continuation of application Ser. No. 08/963,825, filed Nov. 4, 1997, now U.S. Pat. No. 6,110,689, which is a continuation of prior application Ser. No. 08/187,319, filed Jan. 21, 1994, now abandoned.

The present invention relates to a method of determining collagen fragments in body fluids. The invention further relates to means, including synthetic peptides, monoclonal and polyclonal antibodies and cell lines, for use in carrying out the method of the invention. Still further, the invention relates to the use of the above method to diagnose the presence of disorders associated with the metabolism of collagen, especially osteoporosis.

BACKGROUND OF THE INVENTION Collagens and Disorders of Collagen Metabolism

Osteoporosis is the most common bone disease in humans. Primary osteoporosis, accompanied by increased susceptibility to fractures, results from a progressive reduction in skeletal bone mass. It is estimated to affect 15-20 million individuals in the USA alone. Its basis is an age-dependent imbalance in bone remodeling, i.e., in the rates of formation and resorption of bone tissue.

In the USA about 1.2 million osteoporosis-related fractures occur in the elderly each year including about 538,000 compression fractures of the spine, about 227,000 hip fractures and a substantial number of early fractured peripheral bones. Between 12 and 20% of the hip fractures are fatal because they cause severe trauma and bleeding, and half of the surviving patients require nursing home care. Total costs from osteoporosis-related injuries now amount to at least $10 billion annually in the USA (Riggs, New England Journal of Medicine 327:620-627 (1992)).

Osteoporosis is most common in postmenopausal women who, on average, lose 15% of their bone mass in the 10 years after menopause. This disease also occurs in men as they get older and in young amenorrheic women athletes. Despite the major, and growing, social and economic consequences of osteoporosis, the availability of reliable assays for measuring bone resorption rates in patients or in healthy subjects is very limited. Other disorders entailing (and correlated with) abnormalities in collagen metabolism include Paget's disease, Marfan's syndrome, osteogenesis imperfecta neoplastic growth in collagenous tissue, dwarfism, rheumatoid arthritis, osteoarthritis and vasculitis syndrome.

Three known classes of human collagen have been described to date. The Class I collagens, subdivided into types. I, II, III, V, and XI, are known to form fibrils. Their full amino-acid sequence (to the extent they have been elucidated) are attached in Appendix A.

Collagen type I accounts for more than 90% of the organic matrix of bone. Therefore, in principle, it is possible to estimate the rate of bone resorption by monitoring the degradation of collagen type I. Likewise, a number of other disease states involving connective tissue can be monitored by determining the degradation of collagen. Examples are collagen type II degradation associated with rheumatoid arthritis and osteoarthritis and collagen type III degradation in vasculitis syndrome.

Amino acid sequences of human type III collagen, human pro 1(II) collagen, and the entire prepro 1(III) chain of human type III collagen and corresponding cDNA clones have been investigated and determined by several groups of researchers; see Loil et al., Nucleic Acids Research 12:9383-9394 (1984); Sangiorgi et al., Nucleic Acids Research 13:2207-2225 (1985); Baldwin et al., Biochem J. 262:521-528 (1989); and Ala-Kokko et al., Biochem. J. 260:509-516 (1989).

Type I, II, and III collagens are all formed in the organism as procollagen molecules, comprising N-terminal and C-terminal propeptide sequences, which are attached to the core collagen molecules. After removal of the propeptides, which occur naturally in vivo during collagen synthesis, the remaining core of the collagen molecules consists largely of a triple-helical domain having terminal telopeptide sequences which are non-triple-helical. These telopeptide sequences have an important function as sites of intermolecular cross-linking of collagen fibrils extracellularly. The alpha-helical region also includes crosslinkable sites. Peptides from this region are part of the present invention.

Intermolecular cross-links provide collagen fibrils with biomechanical stability. The formation of these cross-links is initiated by modification of lysine and hydroxylysine residues to the corresponding aldehydes. Several of these residues located on adjacent chains of collagen will spontaneously form different intermolecular cross-links. The exact position of the sites for cross-linking on collagen telopeptides and from the helical region has been previously described. See, for example, Kühn, K., in Immunochemistry of the Extracellular Matrix 1:1-29, CRC Press, Inc., Boca Raton, Fla. (1982), Eyre, D. R., Ann. Rev. Biochem. 53:717-48 (1984) or U.S. Pat. No. 5,140,103). Furthermore, the amino acid sequences of some potential sites for cross-linking in type I, II, and III collagen are given in Table 1 below.

The fibrous proteins, collagen and elastin, are cross-linked by a unique mechanism based on aldehyde formation from lysine or hydroxylysine side chains. Four homologous loci of cross-linking are evident in molecules of type I, II and III collagens (for review see Kühn, K., in Immunochemistry of the Extracellular Matrix 1:1-29 (1982)). Two are aldehyde sites, one in each telopeptide region. The other two sites are hydroxylysine symmetrically placed at about 90 residues from each end of the molecule. When collagen molecules pack into fibrils, these latter sites in the helical region align and react with telopeptide aldehydes in adjacent molecules. There is now strong evidence that 3-hydroxypyridinium residues are the mature cross-link coming from hydroxylysine-derived aldehydes. The mature cross-linking residues of the other pathway, i.e. from aldehyde formation of lysine residues, is, however, still unknown.

Prior Art Assays for Collagen Degradation

In the past, assays have been developed for monitoring degradation of collagen in vivo by measuring various biochemical markers, some of which have been degradation products of collagen. However, none of these methods are based upon the use of immunological binding partners in the form of antibodies which are immunoreactive with synthetic peptides having a sequence essentially derived from collagen fragments having crosslinkable sites.

For example, hydroxyproline, an amino acid largely restricted to collagen, and the principal structural protein in bone and all other connective tissues, is excreted in urine. Its excretion rate is known to be increased in certain conditions, notably Paget's disease, a metabolic bone disorder in which bone turnover is greatly increased, as discussed further below.

For this reason, urinary hydroxyproline has been used extensively as an amino acid marker for collagen degradation; Singer, F. R. et al., Metabolic Bone Disease, Vol. II (eds. Avioli, L. V., and Kane, S. M.), 489-575 (1978), Academic Press, New York.

U.S. Pat. No. 3,600,132 discloses a process for the determination of hydroxyproline in body fluids such as serum, urine, lumbar fluid and other intercellular fluids in order to monitor deviations in collagen metabolism. The patent states that hydroxyproline correlates with increased collagen anabolism or catabolism associated with pathological conditions such as Paget's disease, Marfan's syndrome, osteogenesis imperfecta, neoplastic growth in collagen tissues and in various forms of dwarfism.

Bone resorption associated with Paget's disease has also been monitored by measuring small peptides containing hydroxyproline, which are excreted in the urine following degradation of bone collagen; Russell et al., Metab. Bone Dis. and Rel. Res. 4 and 5:255-262 (1981), and Singer, F. R., et al., supra.

In the case of Paget's disease, the increased urinary hydroxyproline probably comes largely from bone degradation; hydroxyproline, however, generally cannot be used as a specific index for bone degradation. Much of the hydroxyproline in urine may come from new collagen synthesis (considerable amounts of the newly made protein are degraded and excreted without ever becoming incorporated into tissue fabric), and from turnover of certain blood proteins as well as other proteins that contain hydroxyproline.

Furthermore, about 80% of the free hydroxyproline derived from protein degradation is metabolized in the liver and never appears in the urine. Kiviriko, K. I., Int. Rev. Connect. Tissue Res. 5:93 (1970), and Weiss, P. H. and Klein, L., J. Clin. Invest. 48:1 (1969). Hydroxyproline is a good marker for osteoporosis, but it is troublesome to handle. It is specific for collagen in bones.

Hydroxylysine and its glycoside derivatives, both peculiar to collagenous proteins, have been considered to be more accurate than hydroxyproline as markers of collagen degradation.

However, for the same reasons described above for hydroxyproline, hydroxylysine and its glycosides are probably equally non-specific markers of bone resorption; Krane, S. M. and Simon, L. S., Develop. Biochem. 22:185 (1981).

Other researchers have measured the cross-linking compound 3-hydroxypyridinium in urine as an index of collagen degradation in joint diseases. See, for background and as examples, Wu and Eyre, Biochemistry 23:1850 (1984); Black et al., Annals of the Rheumatic Diseases 48:641-644 (1989); Robins et al.; Annals of the Rheumatic Diseases 45:969-973 (1986); and Seibel et al., The Journal of Dermatology 16:964 (1989). In contrast to the present invention, these prior researchers have hydrolyzed peptides from body fluids and then looked for the presence of individual 3-hydroxypyridinium residues.

Assays for determination of the degradation of type I, II, and III collagen are disclosed in U.S. Pat. Nos. 4,973,666 and 5,140,103. However, both these patents are restricted to collagen fragments containing the cross-linker 3-hydroxypyridinium, whereas the present invention does not rely on the presence or absence of this particular cross-linking structure. Furthermore, the above-mentioned assays require tedious and complicated purifications from urine of collagen fragments containing 3-hydroxypyridinium to be used for the production of antibodies and for antigens in the assays.

At present very few clinical data using the approach described in U.S. Pat. Nos. 4,973,666 and 5,140,103 are available. Particularly, no data concerning the correlation between the urinary concentration (as determined by methods described in the above-mentioned patents) of 3-hydroxypyridinium containing telopeptides of type I collagen and the actual bone loss (as determined by repeated measurements by bone densitometry) are published. The presence of 3-hydroxypyridinium containing telopeptides in urine requires the proper formation in bone tissue of this specific cross-linking structure at various times before the bone resorbing process. Very little information on these processes is available and the present invention seeks -to circumvent this dependance of the correct formation of the cross-linking structure. Furthermore, preliminary data indicate that in one embodiment of-the present invention a major fraction of the molecules reactive in the assay has a molecular weight of more than 4,000 daltons. On the contrary, only molecules with a molecular weight below 2.000 daltons are identified in urine with the monoclonal antibody used in the assay; Hanson et al., Journal of Bone and Mineral Research 7:1251-1258 (1992). This demonstrates that the method according to the present invention has a very different profile of reactivities, i.e. it detects very different molecules, compared to methods described in the two above-mentioned U.S. patents.

None of the above researchers have reported specifically assaying a crosslinkable collagen fragment that is naturally produced in vivo upon collagen degradation, as in the present invention.

GB patent application No. 2,205,643 reports that the degradation of type III collagen in the body can be quantitatively determined by measuring the concentration of an N-terminal telopeptide from type III collagen in a body fluid. This method does not relate to methods employing antibodies reactive with specific, low molecular weight sequences around crosslinkable structures. Instead, the method uses antibodies generated to N-terminal telopeptides released by bacterial collagenase degradation of type III collagen, said telopeptides being labelled and used in the assay.

There are a number of reports indicating that collagen degradation can be measured by quantitating certain procollagen peptides. Propeptides are distinguished from telopeptides and alpha-helical region of the collagen core by their location in the procollagen molecule and the timing of their cleavage in vivo; see U.S. Pat. Nos. 4,504,587; 4,312,853; Pierard et al., Analytical Biochemistry 141:127-136 (1984); Niemela, Clin. Chem. 31/8:1301-1304 (1985); and Rohde et al., European Journal of Clinical Investigation 9:451-459 (1979).

U.S. Pat. No. 4,778,768 relates to a method of determining changes occurring in articular cartilage involving quantifying proteoglycan monomers or antigenic fragments thereof in a synovial fluid sample. This U.S. patent does not relate to detecting collagen fragments derived from degraded collagen.

Dodge, J. Clin, Invest. 83:647-661 (1981) discloses methods for analyzing type II collagen degradation utilizing a polyclonal antiserum that specifically reacts with unwound alpha-chains and cyanogen bromide-derived peptides of human and bovine type II collagens. Contrary to the present invention the degradation products of collagen were not detected in a body fluid, but histochemically by staining of cell cultures, i.e. by “in situ” detection. The main difference between Dodge and the present invention is that Dodge measures type II collagen degradation in situ. By “in situ” is meant a determination carried out in the cells or tissue in which the degradation takes place. There is quite a fundamental difference between this determination and a method based upon tracing a marker in vitro, e.g. in the urine.

None of these references specify the structures of particular telopeptide or alpha-helical degradation products that could be measured to determine the amount of degraded fibrillar collagen in vivo.

SUMMARY OF THE INVENTION

The present invention is based on the discovery of the presence of particular collagen fragments in body fluids of patients and normal human subjects. The collagen fragments are generated upon collagen degradation and are partly characterized by the presence of potential sites for cross-linking, e.g. by the presence of lysine or hydroxylysine (Kühn, K., Immunochemistry of the Extracellular Matrix 1:1-29 (1982)). It is believed that a fraction of the collagen fragments measured by the assays embodied in the present invention are normally covalently linked in vivo to other peptide fragments through different, unidentified or already identified cross-links.

The method of the present invention may be used for determination of the degradation of human collagen of type I, II, and III.

The present invention provides a method of assessing the degradation of collagen based on a determination of the presence and quantity of a particular class of collagen fragments produced in vivo upon collagen degradation; and a comparison of the detected collagen fragments to those of a predetermined standard developed by measuring the same class of collagen fragments in normal individuals, i.e. individuals not afflicted with a disorder affecting collagen metabolism, said individuals being sex- and age-matched with the subjects being tested.

The present invention uses antibodies immunoreactive with synthetic peptides without these cross-linking structures. Accordingly, it is believed that collagen fragments (corresponding to the synthetic peptides) with or without actual cross-links, but with crosslinkable sites, are measured in the assays embodied in the present invention.

In a preferred embodiment, the method is based on the competitive binding of collagen fragments in body fluids and of synthetic peptides essentially derived from collagen to immunological binding partners.

The present invention provides new and very simple procedures for the detection (qualitative and quantitative) of collagen fragments generated upon collagen degradation.

For purposes of the present invention, as disclosed and claimed herein, the following terms are as defined below:

“Antibody”: A monoclonal or polyclonal antibody or immunoreactive fragment thereof (i.e. capable of binding the same antigenic determinant), including—but not limited to—Fab, Fab′, and F(ab′)2 fragments.

“Crosslinkable sites”: loci in collagen telopeptide or helix amino acid sequences containing lysine or hydroxylysine residues which can form cross-links with telopeptides or helical amino acid sequences of other collagen molecules in vivo.

“Crosslinkable peptides”: peptides containing a fragment of the collagen sequence including at least one crosslinkable site.

Test kit: A combination of reagents and instructions for use in conducting an assay.

“Essentially derived” (about structures) Structures with similar antigenicity, i.e. with an ability, above the level of a non-related peptide, to inhibit the binding of any of the mentioned synthetic peptides to an antibody immunoreactive with said synthetic peptide.

It is contemplated that the method may also be used for assaying collagen fragments in animal body fluids, e.g. for determination of the collagen metabolism. It also can be used during clinical testing of new drugs to assess the impact of these drugs on collagen metabolism.

More specifically, the present invention relates to methods for assaying collagen fragments by the use of synthetic peptides corresponding to the above-mentioned sequences of collagen. Generally, these synthetic peptides will have fewer amino acid residues than the entire collagen molecule, often they will have fewer than 10 amino acids. Also, the synthetic peptides, corresponding to molecules present in body fluids, e.g. urine, will have potential sites for cross-linking, preferably lysine or hydroxylysine, incorporated in the structure.

The present invention comprises the determination of collagen fragments by the use of antibodies which are immunoreactive with the above-mentioned synthetic peptides, said peptides each having a sequence derived from collagen fragments having crosslinkable sites.

The invention also includes cell lines (e.g. hybridomas) that produce monoclonal antibodies immunoreactive with the above-mentioned synthetic peptides. The invention further includes monoclonal antibodies produced by the fused cell hybrids, and those antibodies (as well as binding fragments thereof, e.g. Fab) coupled to a detectable marker. Examples of detectable markers include, but are not limited to, enzymes, chromophores, fluorophores, coenzymes, enzyme inhibitors, chemiluminescent materials, paramagnetic metals, spin labels and radioisotopes.

The methods of the invention involve quantitating in a body fluid the concentration of particular collagen fragments derived from collagen degradation. In a representative assay, collagen fragments in the patient's body fluid and a synthetic peptide immobilized on a solid surface are contacted with an immunological binding partner which is immunoreactive with the synthetic peptide. Suitable body fluids are e.g. human urine, blood, serum, plasma and synovial fluid. It is contemplated that the method may also be used e.g. on saliva and sweat. The body fluid may be used as it is, or it may be purified prior to the contacting step. This purification step may be accomplished using a number of standard procedures, including, but not limited to, cartridge adsorption and elution, molecular sieve chromatography, dialysis, ion exchange, alumina chromatography, hydroxyapatite chromatography, and combinations thereof.

The present invention is based on the discovery of simple procedures for quantitation of collagen fragments in body fluids. In a representative procedure, synthetic peptides containing potential sites for cross-linking, are used for the raising of antibodies and subsequently incorporated in the assay for quantitation of collagen fragments generated in vivo by collagen degradation.

The invention also includes test kits useful for quantitating in a body fluid the amount of collagen fragment derived from the degradation of collagen. The kits comprise at least one immunological binding partner, e.g. a monoclonal or polyclonal antibody specific for a peptide derived from the degradation of collagen. If desired, the immunological binding partner of the test kit may be coupled to detectable markers such as the ones described above.

The invention is described in more detail below. Reference is made to the appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1, 2 and 3 are typical standard curves for the α1(I)C1 immunoassay (FIG. 1), the a1(I)N1 immunoassay (FIG. 2) and the α2(I)N1 immunoassay (FIG. 3) to be described in more detail in the examples;

FIG. 4 shows the correlation between total pyridinolin (HPLC) and the α1(I)C1 immunoassay,

FIG. 5 shows the correlation between total pyridinolin (HPLC) and the α1(I)N1 immunoassay,

FIG. 6 shows the individual values of the measurement of α1(I)C1 peptide in urine samples from normal, age-matched women, and

FIG. 7 shows the individual values of the measurement of urine samples from women on a hormone replacement therapy and placebo in the α1(I)C1 immunoassay.

DETAILED DESCRIPTION AND BEST MODE OF CARRYING OUT THE INVENTION

In a preferred embodiment of the method according to the invention, the assaying of type I, II and III collagen fragments in urine is performed by an inhibition ELISA (enzyme linked immunosorbent assay) by metering off a sample of urine and contacting the sample with a synthetic peptide having a sequence derived from collagen and with an antibody, which is immunoreactive with the synthetic peptide. The synthetic peptide is immobilized on a solid support. The antibody is raised against the synthetic peptide.

The combined reagents and sample are incubated, and a peroxidase-conjugated (revealing) antibody is added. After another incubation, a peroxidase substrate solution is added. Following short final incubation, the enzyme reaction is stopped, and the absorbance is measured at 450 nm and compared with a standard curve obtained with standard solutions by the same procedure.

Synthetic peptides are used for the preparation of standards. The concentration of synthetic peptide in a stock solution of the relevant synthetic peptide is determined by quantitative amino acid determination. A two-fold dilution of the stock solution is prepared and subsequently used for the construction of the standard curve in the inhibition ELISA.

Preparation of Synthetic Peptides

The preparation of synthetic peptides may be performed according to procedures well known in the art, e.g. by solid-phase peptide synthesis techniques commonly described as “Merrifield synthesis”. Also classical solution phase techniques may be used. Sequences of interest include potential sites for cross-linking (see for example Kühn, K., in Immunochemistry of the Extracellular Matrix 1:1-29 (1982), Eyre, D. R., Ann. Rev. Biochem. 53:717-48 (1984), or U.S. Pat. No. 5,140,103). Examples of such peptides sequences are given in table 1 below.

Regarding the synthetic peptides, it is possible to omit (or add) one or more amino acid residues from (or to) the crosslinkable site sequences without substantial loss of the ability to (a) raise antibodies recognizing the corresponding native collagen fragment or (b) inhibit the bindings of such antibodies to the native fragment. It is possible to use longer collagen fragments and/or chimeric peptides to raise the antibodies and, in principle, it is not necessary to use the same peptide as the immunogen and the competitor in the assay.

TABLE 1

Examples of Amino acid sequences with potential sites for cross-linking in various types of collagen to be used as a basis for synthetic peptides according to the present invention

Collagen Type I

Potential sites in telopeptides: N

α1(I)N-term.

Asp-Glu-Lys-Ser-Thr-Gly-Gly (α1(I)N1) (SEQ. ID NO: 1)

α1(I)C-term.

Glu-Lys-Ala-His-Asp-Gly-Gly-Arg (α1(I)C1) (SEQ. ID NO: 2)

α2(I)N-term.

Gln-Tyr-Asp-Gly-Lys-Gly-Val-Gly (α2(I)N1) (SEQ. ID NO: 3)

α2(I)C-term.

no potential sites

Potential sites in helix;

α1(I)(near N)

Gly-Met-Lys-Gly-His-Arg (SEQ. ID NO: 4)

α1(I)(near C)

Gly-Ile-Lys-Gly-His-Arg (SEQ. ID NO: 5)

α2(I)(near N)

Gly-Phe-Lys-Gly-Ile-Arg (SEQ. ID NO: 6)

α2(I)(near C)

Gly-Leu-Pro-Gly-Leu-Lys-Gly-His-Asn (SEQ. ID NO: 7)

Collagen Type II

Potential sites in telopeptides: NC

α1(II) N-term.

Pro-Gly-Pro-Lys-Gly-Glu (SEQ. ID NO: 8)

Gly-Gln-Lys-Gly-Glu-Pro (SEQ. ID NO: 9)

Gly-Asp-Ile-Lys-Asp-Ile-Val (SEQ. ID NO: 10)

α1(II) C-term.

Glu-Lys-Gly-Pro-Asp (SEQ. ID NO: 11)

Potential sites in helix:

α1(II) (near N)

Gly-Val-Lys (SEQ. ID NO: 12)

Pro-Gly-Val-Lys-Gly (SEQ. ID NO: 13)

Collagen Type III

Potential sites in telopeptides: NC

α1(III) N-term.

Asp-Val-Lys-Ser-Gly-Val (SEQ. ID NO: 14)

α1(III) C-term.

Glu-Lys-Ala-Gly-Gly-Phe-Ala (SEQ. ID NO: 15)

Potential sites in helix:

α1(III) (near N)

Gly-Phe-Pro-Gly-Met-Lys-Gly-His-Arg (SEQ. ID NO: 16)

α1(III) (near C)

Gly-Ala-Ala-Gly-Ile-Lys-Gly-His-Arg (SEQ. ID NO: 17)

Preparation of Antibodies

The methods for preparation of both monoclonal and polyclonal antibodies are well known in the art. For example, see Campbell, A. M., Laboratory Techniques in Biochemistry and Molecular Biology, Vol. 13 (1986). It is possible to produce antibodies to synthetic peptides by immunization. However, because of the relatively small molecular weight of these compounds it is preferred that the hapten be conjugated to a carrier molecule. Suitable carrier molecules include, but are not limited to, bovine serum albumin, thyroglobulin, ovalbumin, tetanus toxoid, and keyhole limpet hemocyanin. The preferred carrier is bovine serum albumin. To present the hapten in its most immunogenic form to the antibody producing cells of the immunized animal a number of alternative coupling protocols can be used. Suitable procedures include, but are not limited to, glutaraldehyde, carbodiimide, and periodate. Preferred binding agents are glutaraldehyde and carbodiimide.

The preparation of antibodies is carried out by conventional techniques including immunization with collagen fragments or synthetic peptides conjugated to a carrier. To improve the immunogenicity it is preferred that the immunogen be mixed with an adjuvant before injection. Examples of adjuvants include, but are not limited to, aluminum hydroxide, Freund's adjuvant, and immune-stimulating complexes (ISCOMs). ISCOMs can be made according to the method described by Morein, B. et al., Nature 308:457-460 (1984).

Either monoclonal or polyclonal antibodies to the hapten carrier molecule can be produced. For the production of monoclonal antibodies it is preferred that mice are immunized. Spleen cells from the immunized mouse are harvested, homogenized, and thereafter fused with cancer cells in the presence of polyethylene glycol to produce a cell hybrid which produces monoclonal antibodies specific for peptide fragments derived from collagen. Suitable cancer cells include, but are not limited to, myeloma, hepatoma, carcinoma, and sarcoma cells. Detailed descriptions of the production of monoclonal antibodies are provided in Goding, J. W., in Monoclonal Antibodies: Principles and Practice, (1986). A preferred preliminary screening protocol comprises the use of synthetic peptides conjugated to a carrier and coated onto the solid surface of a microtitre plate.

For the preparation of polyclonal antibodies, which are reactive with peptide fragments derived from collagen, different animal species can be immunized. Suitable species include, but are not limited to, chicken, rabbit and goat. Chicken and rabbit are preferred.

Antibody fragments are prepared by methods known in the art (see E. Ishikawa, J. of Immunoassay 3:209-327, 1983).

Conduct of Immunoassays

Accordingly, by utilization of an immunoassay with the antibodies prepared as above it is possible to assay a biological fluid sample without prior fractionation or hydrolysis. The specificity for the desired collagen in the biological fluid is supplied by the antibody in combination with the use of a synthetic peptide (against which the antibody was raised or in any event with which the antibody is immunochemically reactive) in the assay construction.

The immunoassays themselves are conducted using any procedure selected from the variety of standard assay protocols generally known in the art. As it is generally understood, the assay is constructed so as to rely on the interaction between the specific immunological binding partner and the desired analyte for specificity and to utilize some means to detect the complex formed by the analyte and the immunological binding partner. The immunological binding partner may be complexed to a solid support and used as a capture immunological binding partner for the analyte. This protocol may be run in a direct form, wherein the formation of analyte/immunological binding partner complex is detected, e.g. by a fluorescent, radioactive or enzymatic label, or it may be run in a competitive format wherein a labelled standard competes with the analyte for the immunological binding partner. The format may also be constructed as an agglutination assay or the complex may be precipitated by addition of a suitable precipitant to the reaction mixture. The specific design of the immunoassay protocol is open to a wide variety of choice, and the number of clinical assay devices and protocols available in the art is multitudinous. For a variety of such protocols, see U.S. Pat. No. 5,001,225.

The antibodies and revealing reagents for the conduct of an immunoassay using standard detection protocols, for example radioisotope labelling, fluorescent labelling or ELISA, either in a direct or competitive format, may conveniently be supplied as kits which include the necessary components and instructions for the assay. In one embodiment of the invention such a kit includes a microtiter plate coated with a relevant synthetic peptide, standard solutions for preparation of standard curve, a urine control for quality testing of the analytical run, rabbit antibodies reactive with the above-mentioned synthetic peptide, anti-rabbit immunoglobulins conjugated to peroxidase, a substrate solution, a stopping solution, a washing buffer and an instruction manual.

Since immunoassays can be constructed using antibodies and specific synthetic peptides, the ratios of the corresponding collagen fragment sequences in an appropriate biological fluid can be determined as well as their individual levels and their total. Thus, the assay can be designed to include antibodies which will result in determination of several native peptide sequences or determination of a single peptide sequence, or any desired combination thereof.

In addition to the use of the herein specified peptides as indicators of bone resorption, bone metabolic balance is advantageously determined by the substantially simultaneous determination of a marker of the formation of bone in the same or other appropriate biological fluid from the same individual. “Substantially simultaneous” means the same day, preferably within 4 hours. For example such markers include osteocalcin (also known as bone GLA protein of BGP), procollagen type I, bone alkaline phosphatase and total alkaline phosphatase. Suitable methods for the determination of these markers can be found, for example, in Delmas, P. D., et al., J. Bone Min. Res. 1:333-337 (1986).

The assay of the present invention which provides an index to determination of the metabolic status of tissues, which generate collagen-derived peptides when degradation occurs, are useful {circumflex over ( )} in a variety of contexts. First, when considering the degradation of type I collagen, the assays are methods to assess an abnormal condition of a subject by indicating, for example, excessive bone resorption. This may show the presence of an osteoporotic condition or the metastatic progress of a malignancy. Other conditions characterized by excessive bone resorption include Paget's disease and hyperparathyroidism. Likewise, a number of other disease states involving connective tissue may be monitored by determination of the degradation of collagen. Examples are collagen type II degradation associated with rheumatoid arthritis and osteoarthritis and collagen type III degradation in vasculitis syndrome. Since the condition of the subject can be monitored continuously, application of these assays can also be used to monitor the progress of therapy administered to treat these or other conditions. Further, the assays can be used as a measure of toxicity, since the administration of toxic substances often results in tissue degradation.

Thus the assays may be applied in any situation wherein the metabolic condition of collagen tissues can be used as an index of the condition, treatment, or effect of substances directly administered to the subject or to which the subject is exposed in the environment.

The following examples are intended to illustrate, but not to limit the invention.

EXAMPLE 1 Immunoassays for Specific Peptide Sequences in Urine

Three peptides (α1(I)C1, α1(I)N1, and α2(I)N1) (see Table 1, p. 13) prepared by solid-phase techniques are used for the preparation of immunogens. For immunization, the peptides are covalently attached to bovine serum albumin using glutaraldehyde reagents and methods well known in the art. Both monoclonal and polyclonal antibodies are raised against the peptides. For production of monoclonal antibodies, Balb/c mice are immunized with peptide-BSA conjugates, and hybridoma cell lines are prepared using standard techniques after fusion of cells from the spleen or lymph nodes with Ag8 myeloma cells. Polyclonal antibodies are raised in rabbits and chicken. Screening of both antisera and hybridoma cell media were performed by ELISA using microtiter plates coated with the appropriate peptide-gelatin conjugate prepared using carbodiimide reagents and methods well known in the art.

Assays for three of the peptide sequences (α1(I)C1, α1(I)N1, and α2(I)N1) in urine are performed by an inhibition ELISA as follows:

Urine samples (10 or 25 l) possibly containing collagen fragments or solutions containing 0.05-15 g peptide/ml as reference standards, respectively, are added to 75 l of immunological binding partners for the peptides diluted 1:5,000-1:20,000 in phosphate buffered saline containing 0.1% Tween-20 detergent (PBS-T) and including 0.1% (w/v) of BSA. Each sample is prepared in duplicate in flat-bottomed, 96-well microtiter plates previously coated with gelatine conjugate containing the appropriate peptide. After 60 minutes, the plates are washed with PBS-T (3 times) and the bound antibodies are detected by standard techniques with a horse radish peroxidase labelled antibody prepared against the species of the primary antibody. Peroxidase substrate is added and the color development is measured at 450 nm in an automated microtiter plate reader after stopping the enzyme reaction using 1 M H3PO4. Samples containing the analyte decrease the binding of primary antibody to the immunobilized peptide in the plate and thus have a reduced color concentration. The amount of analyte in the sample is quantified with reference to previously established curves from standards included on each plate computed using log-lin plots. FIGS. 1, 2 and 3 show typical standard curves for the α1(I)C1 immunoassay (FIG. 1), α1(I)N1 immunoassay (FIG. 2), and α2(I)N1 immunoassay (FIG. 3).

EXAMPLE 2 Correlation to Pyridinolin Determination on HPLC

On a number of unselected urine samples the concentration of total pyridinolin (HPLC method, see for example Uebelhart, D., Bone and Mineral 8:87-96 (1990)) was measured. Values obtained in this HPLC system were correlated to the values obtained in two immunoassays (α1(I)C1 peptide and α1(I)N1 peptide).

FIG. 4 shows the correlation between total pyridinolin (HPLC) and α1(I)C1 immunoassay (n=59). The correlation calculated by linear regression analysis is r=0.80.

FIG. 5 shows the correlation between total pyridinolin (HPLC) and α1(I)N1 immunoassay (n=36). The correlation calculated by linear regression analysis is r=0.95.

EXAMPLE 3 Clinical Results

The immunoassay procedure (using the α1(I)C1 peptide) set forth in Example 1 was applied to urine samples from different individuals, and the amount of analyte was quantitated. The values obtained were related to the level of urinary creatinine in the urine sample as is commonly done for urine assays. The values obtained for normal, age-matched women (premenopausal and postmenopausal) are shown in Table 2.

TABLE 2 Measurement of α1 (I)C1 peptide in urine samples from normal, age-matched women (premenopausal and postmenopausal) Group α1 (I)C1 petide (g/mol creatinine) Premenopausal (n = 104) 0.263 ± 0.143 Postmenopausal (n = 180) 0.426 ± 0.190

For individual values see FIG. 6.

The difference between the premenopausal and the post-menopausal values is highly significant (P<0.0001).

The z-score of a quantitative test procedure shows the ability of the procedure to distinguish between two populations. Table 3 below shows the z-score of the IC1 immunoassay and the state of the art measurement of pyridinolin on HPLC when applied to the same set of urine samples from normal, age-matched premenopausal (n=104) and postmenopausal women (n=180).

TABLE 3 Z-scores obtained for two different test procedures (total pyridinolin (HPLC) and α1 (I)C1 immunoassay) when applied to urine samples from normal, age-matched women (premenopausal and postmenopausal) Test procedure Z-score α1 (i)C1 immunoassay 1.14 Total pyridinolin (HPLC) 1.25

As can be seen from Table 3, the abilities of the two methods to distinguish between patient populations are approximately alike.

For an assay to be used as an index of bone resorption it is very important to be able to measure the impact of a hormone replacement therapy (HRT). Table 4 shows the results from the α1(I)C1 immunoassay in such a study.

TABLE 4 Measurement of urine samples from women on a hormone replacement therapy and placebo in the α1 (I)C1 immunoassay. Values given as percent of t = 0 α1 (I)c1 peptide (μg/mol creatinine) Group t = 0 t = 12 months HRT (n = 92) 0.457 ± 0.176 0.176 ± 0.103 Placebo (n = 45) 0.459 ± 0.209 0.402 ± 0.187

For individual values see FIG. 7.

A highly significant drop in the group receiving HRT is seen after 12 months (P<0.001).

All cited patents, patent applications and literature are incorporated by reference in their entirety. In case of conflict, however, the present disclosure controls.

The invention has been described above by reference to specific embodiments. It will be apparent to those skilled in the art, however, that many additions, deletions and modifications are possible without departing from the spirit of the invention as claimed below.

21 7 amino acids amino acid linear peptide N-terminal Homo sapiens COLLAGEN TYPE I-alpha 1 -N term 1 Asp Glu Lys Ser Thr Gly Gly 1 5 8 amino acids amino acid linear peptide C-terminal Homo sapiens COLLAGEN TYPE I -ALPHA 1- c TERMINAL 2 Glu Lys Ala His Asp Gly Gly Arg 1 5 8 amino acids amino acid linear peptide N-terminal Homo sapiens COLLAGEN TYPE I - ALPHA 2- N TERMINAL 3 Gln Tyr Asp Gly Lys Gly Val Gly 1 5 6 amino acids amino acid linear peptide internal Homo sapiens COLLAGEN TYPE I -ALPHA 1- NEAR N 4 Gly Met Lys Gly His Arg 1 5 6 amino acids amino acid linear peptide C-terminal Homo sapiens COLLAGEN TYPE I -ALPHA 1 NEAR c 5 Gly Ile Lys Gly His Arg 1 5 6 amino acids amino acid linear peptide internal Homo sapiens COLLAGEN TYPE I- ALPHA 2- NEAR N 6 Gly Phe Lys Gly Ile Arg 1 5 9 amino acids amino acid linear peptide internal Homo sapiens COLLAGEN TYPE I - ALPHA 2 - NEAR C 7 Gly Leu Pro Gly Leu Lys Gly His Asn 1 5 6 amino acids amino acid linear peptide N-terminal Homo sapiens COLLAGEN TYPE II- ALPHA 1- N TERM 8 Pro Gly Pro Lys Gly Glu 1 5 6 amino acids amino acid linear peptide N-terminal Homo sapiens COLLAGEN TYPE II- ALPHA 1 N2 9 Gly Gln Lys Gly Glu Pro 1 5 7 amino acids amino acid linear peptide N-terminal Homo sapiens COLLAGEN TYPE II - ALPHA 1- N3 10 Gly Asp Ile Lys Asp Ile Val 1 5 5 amino acids amino acid linear peptide C-terminal Homo sapiens COLLAGEN TYPE II - ALPHA 1 -C TERM 11 Glu Lys Gly Pro Asp 1 5 3 amino acids amino acid linear peptide internal Homo sapiens COLLAGEN TYPE II - ALPHA 1 - NEAR N 12 Gly Val Lys 1 5 amino acids amino acid linear peptide internal Homo sapiens COLLAGEN TYPE II - ALPHA 1 -NEAR N2 13 Pro Gly Val Lys Gly 1 5 6 amino acids amino acid linear peptide N-terminal Homo sapiens COLLAGEN TYPE III -ALPHA 1 - N TERM 14 Asp Val Lys Ser Gly Val 1 5 7 amino acids amino acid linear peptide C-terminal Homo sapiens COLLAGEN TYPE III - ALPHA 1 - C TERM 15 Glu Lys Ala Gly Gly Phe Ala 1 5 9 amino acids amino acid linear peptide internal Homo sapiens COLLAGEN TYPE III - ALPHA 1 - NEAR N 16 Gly Phe Pro Gly Met Lys Gly His Arg 1 5 9 amino acids amino acid linear peptide internal Homo sapiens COLLAGEN TYPE III - ALPHA 1 - NEAR C 17 Gly Ala Ala Gly Ile Lys Gly His Arg 1 5 1341 amino acids amino acid linear protein Homo sapiens COLLAGEN ALPHA 1 (I) 18 Met Phe Ser Phe Val Asp Leu Arg Leu Leu Leu Leu Leu Ala Ala Thr 1 5 10 15 Ala Leu Leu Thr His Gly Gln Glu Glu Gly Gln Val Glu Gly Gln Asp 20 25 30 Glu Asp Ile Pro Pro Ile Thr Cys Val Gln Asn Gly Leu Arg Tyr His 35 40 45 Asp Arg Asp Val Trp Lys Pro Glu Pro Cys Gln Ile Cys Val Cys Asp 50 55 60 Asn Gly Lys Val Leu Cys Asp Asp Val Ile Cys Asp Glu Thr Lys Asn 65 70 75 80 Cys Pro Gly Ala Glu Val Pro Glu Gly Glu Cys Cys Pro Val Cys Pro 85 90 95 Asp Gly Ser Glu Ser Pro Thr Asp Gln Glu Thr Thr Gly Val Glu Gly 100 105 110 Pro Lys Gly Asp Thr Gly Pro Arg Gly Pro Arg Gly Pro Ala Gly Pro 115 120 125 Pro Gly Arg Asp Gly Ile Pro Gly Gln Pro Gly Leu Pro Gly Pro Pro 130 135 140 Gly Pro Pro Gly Pro Pro Gly Pro Pro Gly Leu Gly Gly Asn Phe Ala 145 150 155 160 Pro Gln Leu Tyr Gly Tyr Asp Glu Lys Ser Thr Gly Gly Ile Ser Val 165 170 175 Pro Gly Pro Met Gly Pro Ser Gly Pro Arg Gly Leu Pro Gly Pro Pro 180 185 190 Gly Ala Pro Gly Pro Glx Gly Phe Glx Gly Pro Pro Gly Glx Pro Gly 195 200 205 Glx Pro Gly Ala Ser Gly Pro Met Gly Pro Arg Gly Pro Pro Gly Pro 210 215 220 Pro Gly Lys Asx Gly Asx Asx Gly Glx Ala Gly Lys Pro Gly Arg Pro 225 230 235 240 Gly Glx Arg Gly Pro Pro Gly Pro Glx Gly Ala Arg Gly Leu Pro Gly 245 250 255 Thr Ala Gly Leu Pro Gly Met Lys Gly His Arg Gly Phe Ser Gly Leu 260 265 270 Asx Gly Ala Lys Gly Asx Ala Gly Pro Ala Gly Pro Lys Gly Glx Pro 275 280 285 Gly Ser Pro Gly Glx Asx Gly Ala Pro Gly Glx Met Gly Pro Pro Gly 290 295 300 Pro Lys Gly Asn Ser Gly Glu Pro Gly Ala Pro Gly Ser Lys Gly Asp 305 310 315 320 Thr Gly Ala Lys Gly Glu Pro Gly Pro Val Gly Val Gln Gly Pro Pro 325 330 335 Gly Pro Ala Gly Glu Glu Gly Lys Arg Gly Ala Arg Gly Glu Pro Gly 340 345 350 Pro Thr Gly Leu Pro Gly Pro Pro Gly Glu Arg Gly Gly Pro Gly Ser 355 360 365 Arg Gly Phe Pro Gly Ala Asp Gly Val Ala Gly Pro Lys Gly Pro Ala 370 375 380 Gly Glu Arg Gly Ser Pro Gly Pro Ala Gly Pro Lys Gly Ser Pro Gly 385 390 395 400 Glu Ala Gly Arg Pro Gly Glu Ala Gly Leu Pro Gly Ala Lys Gly Leu 405 410 415 Thr Gly Ser Pro Gly Ser Pro Gly Pro Asp Gly Lys Thr Gly Pro Pro 420 425 430 Gly Pro Ala Gly Gln Asp Gly Arg Pro Gly Pro Pro Gly Pro Pro Gly 435 440 445 Ala Arg Gly Gln Ala Gly Val Met Gly Phe Pro Gly Pro Lys Gly Ala 450 455 460 Ala Gly Glu Pro Gly Lys Ala Gly Glu Arg Gly Val Pro Gly Pro Pro 465 470 475 480 Gly Ala Val Gly Pro Ala Gly Lys Asp Gly Glu Ala Gly Ala Gln Gly 485 490 495 Pro Pro Gly Pro Ala Gly Pro Ala Gly Glu Arg Gly Glu Gln Gly Pro 500 505 510 Ala Gly Ser Pro Gly Phe Gln Gly Leu Pro Gly Pro Ala Gly Pro Pro 515 520 525 Gly Glu Ala Gly Lys Pro Gly Glu Gln Gly Val Pro Gly Asp Leu Gly 530 535 540 Ala Pro Gly Pro Ser Gly Ala Arg Gly Glu Arg Gly Phe Pro Gly Glu 545 550 555 560 Arg Gly Val Gln Gly Pro Pro Gly Pro Ala Gly Pro Arg Gly Ala Asn 565 570 575 Gly Ala Pro Gly Asn Asp Gly Ala Lys Gly Asp Ala Gly Ala Pro Gly 580 585 590 Ala Pro Gly Ser Gln Gly Ala Pro Gly Leu Gln Gly Met Pro Gly Glu 595 600 605 Arg Gly Ala Ala Gly Leu Pro Gly Pro Lys Gly Asp Arg Gly Asp Ala 610 615 620 Gly Pro Lys Gly Ala Asp Gly Ser Pro Gly Lys Asp Gly Val Arg Gly 625 630 635 640 Leu Thr Gly Pro Ile Gly Pro Pro Gly Pro Ala Gly Ala Pro Gly Asp 645 650 655 Lys Gly Glu Ser Gly Pro Ser Gly Pro Ala Gly Pro Thr Gly Ala Arg 660 665 670 Gly Ala Pro Gly Asp Arg Gly Glu Pro Gly Pro Pro Gly Pro Ala Gly 675 680 685 Phe Ala Gly Pro Pro Gly Ala Asp Gly Gln Pro Gly Ala Lys Gly Glu 690 695 700 Pro Gly Asp Ala Gly Ala Lys Gly Asp Ala Gly Pro Pro Gly Pro Ala 705 710 715 720 Gly Pro Ala Gly Pro Pro Gly Pro Ile Gly Asn Val Gly Ala Pro Gly 725 730 735 Ala Lys Gly Ala Arg Gly Ser Ala Gly Pro Pro Gly Ala Thr Gly Phe 740 745 750 Pro Gly Ala Ala Gly Arg Val Gly Pro Pro Gly Pro Ser Gly Asn Ala 755 760 765 Gly Pro Pro Gly Pro Pro Gly Pro Ala Gly Lys Glu Gly Gly Lys Gly 770 775 780 Pro Arg Gly Glu Thr Gly Pro Ala Gly Arg Pro Gly Glu Val Gly Pro 785 790 795 800 Pro Gly Pro Pro Gly Pro Ala Gly Glu Lys Gly Ser Pro Gly Ala Asp 805 810 815 Gly Pro Ala Gly Ala Pro Gly Thr Pro Gly Pro Gln Gly Ile Ala Gly 820 825 830 Gln Arg Gly Val Val Gly Leu Pro Gly Gln Arg Gly Glu Arg Gly Phe 835 840 845 Pro Gly Leu Pro Gly Pro Ser Gly Glu Pro Gly Lys Gln Gly Pro Ser 850 855 860 Gly Ala Ser Gly Glu Arg Gly Pro Pro Gly Pro Met Gly Pro Pro Gly 865 870 875 880 Leu Ala Gly Pro Pro Gly Glu Ser Gly Arg Glu Gly Ala Pro Gly Ala 885 890 895 Glu Gly Ser Pro Gly Arg Asp Gly Ser Pro Gly Ala Lys Gly Asp Arg 900 905 910 Gly Glu Thr Gly Pro Ala Gly Pro Pro Gly Ala Xaa Gly Ala Xaa Gly 915 920 925 Ala Pro Gly Pro Val Gly Pro Ala Gly Lys Ser Gly Asp Arg Gly Glu 930 935 940 Thr Gly Pro Ala Gly Pro Ala Gly Pro Val Gly Pro Ala Gly Ala Arg 945 950 955 960 Gly Pro Ala Gly Pro Gln Gly Pro Arg Gly Asp Lys Gly Glu Thr Gly 965 970 975 Glu Gln Gly Asp Arg Gly Ile Lys Gly His Arg Gly Phe Ser Gly Leu 980 985 990 Gln Gly Pro Pro Gly Pro Pro Gly Ser Pro Gly Glu Gln Gly Pro Ser 995 1000 1005 Gly Ala Ser Gly Pro Ala Gly Pro Arg Gly Pro Pro Gly Ser Ala Gly 1010 1015 1020 Ala Pro Gly Lys Asp Gly Leu Asn Gly Leu Pro Gly Pro Ile Gly Pro 1025 1030 1035 1040 Pro Gly Pro Arg Gly Arg Thr Gly Asp Ala Gly Pro Val Gly Pro Pro 1045 1050 1055 Gly Pro Pro Gly Pro Pro Gly Pro Pro Gly Pro Pro Ser Ala Gly Phe 1060 1065 1070 Asp Phe Ser Phe Leu Pro Gln Pro Pro Gln Glu Lys Ala His Lys Gly 1075 1080 1085 Gly Arg Tyr Tyr Arg Ala Asp Asp Ala Asn Val Val Arg Asp Arg Asp 1090 1095 1100 Leu Glu Val Asp Thr Thr Leu Lys Ser Leu Ser Gln Gln Ile Glu Asn 1105 1110 1115 1120 Ile Arg Ser Pro Glu Gly Xaa Arg Lys Asn Pro Ala Arg Thr Cys Arg 1125 1130 1135 Asp Leu Lys Met Cys His Ser Asp Trp Lys Ser Gly Glu Tyr Trp Ile 1140 1145 1150 Asp Pro Asn Gln Gly Cys Asn Leu Asp Ala Ile Lys Val Phe Cys Asn 1155 1160 1165 Met Glu Thr Gly Glu Thr Cys Val Tyr Pro Thr Gln Pro Ser Val Ala 1170 1175 1180 Gln Lys Asn Trp Tyr Ile Ser Lys Asn Pro Lys Asp Lys Asp Arg His 1185 1190 1195 1200 Val Trp Phe Gly Glu Ser Met Thr Asp Gly Phe Gln Phe Glu Tyr Gly 1205 1210 1215 Gly Gln Gly Ser Asp Pro Ala Asp Val Ala Ile Gln Leu Thr Phe Leu 1220 1225 1230 Arg Leu Met Ser Thr Glu Ala Ser Gln Asn Ile Thr Tyr His Cys Lys 1235 1240 1245 Asn Ser Val Ala Tyr Met Asp Gln Gln Thr Gly Asn Leu Lys Lys Ala 1250 1255 1260 Leu Leu Leu Xaa Gly Ser Asn Glu Ile Glu Ile Arg Ala Glu Gly Asn 1265 1270 1275 1280 Ser Arg Phe Thr Tyr Ser Val Thr Val Asp Gly Cys Thr Ser His Thr 1285 1290 1295 Gly Ala Trp Gly Lys Thr Val Ile Glu Tyr Lys Thr Thr Lys Ser Ser 1300 1305 1310 Arg Leu Pro Ile Ile Asp Val Ala Pro Leu Asp Val Gly Ala Pro Asp 1315 1320 1325 Gln Glu Phe Gly Phe Asp Val Gly Pro Val Cys Phe Leu 1330 1335 1340 1366 amino acids amino acid linear protein Homo sapiens collagen alpha 2- type I 19 Met Leu Ser Phe Val Asp Thr Arg Thr Leu Leu Leu Leu Ala Val Thr 1 5 10 15 Leu Cys Leu Ala Thr Cys Gln Ser Leu Gln Glu Glu Thr Val Arg Lys 20 25 30 Gly Pro Ala Gly Asp Arg Gly Pro Arg Gly Glu Arg Gly Pro Pro Gly 35 40 45 Pro Pro Gly Arg Asp Gly Glu Asp Gly Pro Thr Gly Pro Pro Gly Pro 50 55 60 Pro Gly Pro Pro Gly Pro Pro Gly Leu Gly Gly Asn Phe Ala Ala Gln 65 70 75 80 Tyr Asp Gly Lys Gly Val Gly Leu Gly Pro Gly Pro Met Gly Leu Met 85 90 95 Gly Pro Arg Gly Pro Pro Gly Ala Ala Gly Ala Pro Gly Pro Gln Gly 100 105 110 Phe Gln Gly Pro Ala Gly Glu Pro Gly Glu Pro Gly Gln Thr Gly Pro 115 120 125 Ala Gly Ala Arg Gly Pro Ala Gly Pro Pro Gly Lys Ala Gly Glu Asp 130 135 140 Gly His Pro Gly Lys Pro Gly Arg Pro Gly Glu Arg Gly Val Val Gly 145 150 155 160 Pro Gln Gly Ala Arg Gly Phe Pro Gly Thr Pro Gly Leu Pro Gly Phe 165 170 175 Lys Gly Ile Arg Gly His Asn Gly Leu Asp Gly Leu Lys Gly Gln Pro 180 185 190 Gly Ala Pro Gly Val Lys Gly Glu Pro Gly Ala Pro Gly Glu Asn Gly 195 200 205 Thr Pro Gly Gln Thr Gly Ala Arg Gly Leu Pro Gly Glu Arg Gly Arg 210 215 220 Val Gly Ala Pro Gly Pro Ala Gly Ala Arg Gly Ser Asp Gly Ser Val 225 230 235 240 Gly Pro Val Gly Pro Ala Gly Pro Asn Gly Ser Ala Gly Pro Pro Gly 245 250 255 Phe Pro Gly Ala Pro Gly Pro Lys Gly Glu Ile Gly Ala Val Gly Asn 260 265 270 Ala Gly Pro Thr Gly Pro Ala Gly Pro Arg Gly Glu Val Gly Leu Pro 275 280 285 Gly Leu Ser Gly Pro Val Gly Pro Pro Gly Asn Pro Gly Ala Asn Gly 290 295 300 Leu Thr Gly Ala Lys Gly Ala Ala Gly Leu Pro Gly Val Ala Gly Ala 305 310 315 320 Pro Gly Leu Pro Gly Pro Arg Gly Ile Pro Gly Pro Pro Gly Ala Ala 325 330 335 Gly Thr Thr Gly Ala Arg Gly Leu Val Gly Glu Pro Gly Pro Ala Gly 340 345 350 Ser Lys Gly Glu Ser Gly Asn Lys Gly Glu Pro Gly Ser Ala Gly Pro 355 360 365 Gln Gly Pro Pro Gly Pro Ser Gly Glu Glu Gly Lys Arg Gly Pro Asn 370 375 380 Gly Glu Ala Gly Ser Ala Gly Pro Pro Gly Pro Pro Gly Leu Arg Gly 385 390 395 400 Ser Pro Gly Ser Arg Gly Leu Pro Gly Ala Asp Gly Arg Ala Gly Val 405 410 415 Met Gly Pro Pro Gly Ser Arg Gly Ala Ser Gly Pro Ala Gly Val Arg 420 425 430 Gly Pro Asn Gly Asp Ala Gly Arg Pro Gly Glu Pro Gly Leu Met Gly 435 440 445 Pro Arg Gly Leu Pro Gly Ser Pro Gly Asn Ile Gly Pro Ala Gly Lys 450 455 460 Glu Gly Pro Val Gly Leu Pro Gly Ile Asp Gly Arg Pro Gly Pro Ile 465 470 475 480 Gly Pro Val Gly Ala Arg Gly Glu Pro Gly Asn Ile Gly Phe Pro Gly 485 490 495 Pro Lys Gly Pro Thr Gly Asp Pro Gly Lys Asn Gly Asp Lys Gly His 500 505 510 Ala Gly Leu Ala Gly Ala Arg Gly Ala Pro Gly Pro Asp Gly Asn Asn 515 520 525 Gly Ala Gln Gly Pro Pro Gly Pro Gln Gly Val Gln Gly Gly Lys Gly 530 535 540 Glu Gln Gly Pro Ala Gly Pro Pro Gly Phe Gln Gly Leu Pro Gly Pro 545 550 555 560 Ser Gly Pro Ala Gly Glu Val Gly Lys Pro Gly Glu Arg Gly Leu His 565 570 575 Gly Glu Phe Gly Leu Pro Gly Pro Ala Gly Pro Arg Gly Glu Arg Gly 580 585 590 Pro Pro Gly Glu Ser Gly Ala Ala Gly Pro Thr Gly Pro Ile Gly Ser 595 600 605 Arg Gly Pro Ser Gly Pro Pro Gly Pro Asp Gly Asn Lys Gly Glu Pro 610 615 620 Gly Val Val Gly Ala Val Gly Thr Ala Gly Pro Ser Gly Pro Ser Gly 625 630 635 640 Leu Pro Gly Glu Arg Gly Ala Ala Gly Ile Pro Gly Gly Lys Gly Glu 645 650 655 Lys Gly Glu Pro Gly Leu Arg Gly Glu Ile Gly Asn Pro Gly Arg Asp 660 665 670 Gly Ala Arg Gly Ala His Gly Ala Val Gly Ala Pro Gly Pro Ala Gly 675 680 685 Ala Thr Gly Asp Arg Gly Glu Ala Gly Ala Ala Gly Pro Ala Gly Pro 690 695 700 Ala Gly Pro Arg Gly Ser Pro Gly Glu Arg Gly Glu Val Gly Pro Ala 705 710 715 720 Gly Pro Asn Gly Phe Ala Gly Pro Ala Gly Ala Ala Gly Gln Pro Gly 725 730 735 Ala Lys Gly Glu Arg Gly Gly Lys Gly Pro Lys Gly Glu Asn Gly Val 740 745 750 Val Gly Pro Thr Gly Pro Val Gly Ala Ala Gly Pro Ala Gly Pro Asn 755 760 765 Gly Pro Pro Gly Pro Ala Gly Ser Arg Gly Asp Gly Gly Pro Pro Gly 770 775 780 Met Thr Gly Phe Pro Gly Ala Ala Gly Arg Thr Gly Pro Pro Gly Pro 785 790 795 800 Ser Gly Ile Ser Gly Pro Pro Gly Pro Pro Gly Pro Ala Gly Lys Glu 805 810 815 Gly Leu Arg Gly Pro Arg Gly Asp Gln Gly Pro Val Gly Arg Thr Gly 820 825 830 Glu Val Gly Ala Val Gly Pro Pro Gly Phe Ala Gly Glu Lys Gly Pro 835 840 845 Ser Gly Glu Ala Gly Thr Ala Gly Pro Pro Gly Thr Pro Gly Pro Gln 850 855 860 Gly Leu Leu Gly Ala Pro Gly Ile Leu Gly Leu Pro Gly Ser Arg Gly 865 870 875 880 Glu Arg Gly Leu Pro Gly Val Ala Gly Ala Val Gly Glu Pro Gly Pro 885 890 895 Leu Gly Ile Ala Gly Pro Pro Gly Ala Arg Gly Pro Pro Gly Ala Val 900 905 910 Gly Ser Pro Gly Val Asn Gly Ala Pro Gly Glu Ala Gly Arg Asp Gly 915 920 925 Asn Pro Gly Asn Asp Gly Pro Pro Gly Arg Asp Gly Gln Pro Gly His 930 935 940 Lys Gly Glu Arg Gly Tyr Pro Gly Asn Ile Gly Pro Val Gly Ala Ala 945 950 955 960 Gly Ala Pro Gly Pro His Gly Pro Val Gly Pro Ala Gly Lys His Gly 965 970 975 Asn Arg Gly Glu Thr Gly Pro Ser Gly Pro Val Gly Pro Ala Gly Ala 980 985 990 Val Gly Pro Arg Gly Pro Ser Gly Pro Gln Gly Ile Arg Gly Asp Lys 995 1000 1005 Gly Glu Pro Gly Glu Lys Gly Pro Arg Gly Leu Pro Gly Phe Lys Gly 1010 1015 1020 His Asn Gly Leu Gln Gly Leu Pro Gly Ile Ala Gly His His Gly Asp 1025 1030 1035 1040 Gln Gly Ala Pro Gly Ser Val Gly Pro Ala Gly Pro Arg Gly Pro Ala 1045 1050 1055 Gly Pro Ser Gly Pro Ala Gly Lys Asp Gly Arg Thr Gly His Pro Gly 1060 1065 1070 Thr Val Gly Pro Ala Gly Ile Arg Gly Pro Gln Gly His Gln Gly Pro 1075 1080 1085 Ala Gly Pro Pro Gly Pro Pro Gly Pro Pro Gly Pro Pro Gly Val Ser 1090 1095 1100 Gly Gly Gly Tyr Asp Phe Gly Tyr Asp Gly Asp Phe Tyr Arg Ala Asp 1105 1110 1115 1120 Gln Pro Arg Ser Ala Pro Ser Leu Arg Pro Lys Asp Tyr Glu Val Asp 1125 1130 1135 Ala Thr Leu Lys Ser Leu Asn Asn Gln Ile Glu Thr Leu Leu Thr Pro 1140 1145 1150 Glu Gly Ser Arg Lys Asn Pro Ala Arg Thr Cys Arg Asp Leu Arg Leu 1155 1160 1165 Ser His Pro Glu Trp Ser Ser Gly Tyr Tyr Trp Ile Asp Pro Asn Gln 1170 1175 1180 Gly Cys Thr Met Glu Ala Ile Lys Val Tyr Cys Asp Phe Pro Thr Gly 1185 1190 1195 1200 Glu Thr Cys Ile Arg Ala Gln Pro Glu Asn Ile Pro Ala Lys Asn Trp 1205 1210 1215 Tyr Arg Ser Ser Lys Asp Lys Lys His Val Trp Leu Gly Glu Thr Ile 1220 1225 1230 Asn Ala Gly Ser Gln Phe Glu Tyr Asn Val Glu Gly Val Thr Ser Lys 1235 1240 1245 Glu Met Ala Thr Gln Leu Ala Phe Met Arg Leu Leu Ala Asn Tyr Ala 1250 1255 1260 Ser Gln Asn Ile Thr Tyr His Cys Lys Asn Ser Ile Ala Tyr Met Asp 1265 1270 1275 1280 Glu Glu Thr Gly Asn Leu Lys Lys Ala Val Ile Leu Gln Gly Ser Asn 1285 1290 1295 Asp Val Glu Leu Val Ala Glu Gly Asn Ser Arg Phe Thr Tyr Thr Val 1300 1305 1310 Leu Val Asp Gly Cys Ser Lys Lys Thr Asn Glu Trp Gly Lys Thr Ile 1315 1320 1325 Ile Glu Tyr Lys Thr Asn Lys Pro Ser Arg Leu Pro Phe Leu Asp Ile 1330 1335 1340 Ala Pro Leu Asp Ile Gly Gly Ala Asp His Glu Phe Phe Val Asp Ile 1345 1350 1355 1360 Gly Pro Val Cys Phe Lys 1365 1418 amino acids amino acid linear protein Homo sapiens COLLAGEN -ALPHA 1 (II) 20 Met Ile Arg Leu Gly Ala Pro Gln Ser Leu Val Leu Leu Thr Leu Leu 1 5 10 15 Val Ala Ala Val Leu Arg Cys Gln Gly Gln Asp Val Arg Gln Pro Gly 20 25 30 Pro Lys Gly Gln Lys Gly Glu Pro Gly Asp Ile Lys Asp Ile Val Gly 35 40 45 Pro Lys Gly Pro Pro Gly Pro Gln Gly Pro Ala Gly Glu Gln Gly Pro 50 55 60 Arg Gly Asp Arg Gly Asp Lys Gly Glu Lys Gly Ala Pro Gly Pro Arg 65 70 75 80 Gly Arg Asp Gly Glu Pro Gly Thr Leu Gly Asn Pro Gly Pro Pro Gly 85 90 95 Pro Pro Gly Pro Pro Gly Pro Pro Gly Leu Gly Gly Asn Phe Ala Ala 100 105 110 Gln Met Ala Gly Gly Phe Asp Glu Lys Ala Gly Gly Ala Gln Leu Gly 115 120 125 Val Met Gln Gly Pro Met Gly Pro Met Gly Pro Arg Gly Pro Pro Gly 130 135 140 Pro Ala Gly Ala Pro Gly Pro Gln Gly Phe Gln Gly Asn Pro Gly Glu 145 150 155 160 Pro Gly Glu Pro Gly Val Ser Gly Pro Met Gly Pro Arg Gly Pro Pro 165 170 175 Gly Pro Pro Gly Lys Pro Gly Asp Asp Gly Glu Ala Gly Lys Pro Gly 180 185 190 Lys Ala Gly Glu Arg Gly Pro Pro Gly Pro Gln Gly Ala Arg Gly Phe 195 200 205 Pro Gly Thr Pro Gly Leu Pro Gly Val Lys Gly His Arg Gly Tyr Pro 210 215 220 Gly Leu Asp Gly Ala Lys Gly Glu Ala Gly Ala Pro Gly Val Lys Gly 225 230 235 240 Glu Ser Gly Ser Pro Gly Glu Asn Gly Ser Pro Gly Pro Met Gly Pro 245 250 255 Arg Gly Leu Pro Gly Glu Arg Gly Arg Thr Gly Pro Ala Gly Ala Ala 260 265 270 Gly Ala Arg Gly Asn Asp Gly Gln Pro Gly Pro Ala Gly Pro Pro Gly 275 280 285 Pro Val Gly Pro Ala Gly Gly Pro Gly Phe Pro Gly Ala Pro Gly Ala 290 295 300 Lys Gly Glu Ala Gly Pro Thr Gly Ala Arg Gly Pro Glu Gly Ala Gln 305 310 315 320 Gly Pro Arg Gly Glu Pro Gly Thr Pro Gly Ser Pro Gly Pro Ala Gly 325 330 335 Ala Ser Gly Asn Pro Gly Thr Asp Gly Ile Pro Gly Ala Lys Gly Ser 340 345 350 Ala Gly Ala Pro Gly Ile Ala Gly Ala Pro Gly Phe Pro Gly Pro Arg 355 360 365 Gly Pro Pro Asp Pro Gln Gly Ala Thr Gly Pro Leu Gly Pro Lys Gly 370 375 380 Gln Thr Gly Lys Pro Gly Ile Ala Gly Phe Lys Gly Glu Gln Gly Pro 385 390 395 400 Lys Gly Glu Pro Gly Pro Ala Gly Pro Gln Gly Ala Pro Gly Pro Ala 405 410 415 Gly Glu Glu Gly Lys Arg Gly Ala Arg Gly Glu Pro Gly Gly Val Gly 420 425 430 Pro Ile Gly Pro Pro Gly Glu Arg Gly Ala Pro Gly Asn Arg Gly Phe 435 440 445 Pro Gly Gln Asp Gly Leu Ala Gly Pro Lys Gly Ala Pro Gly Glu Arg 450 455 460 Gly Pro Ser Gly Leu Ala Gly Pro Lys Gly Ala Asn Gly Asp Pro Gly 465 470 475 480 Arg Pro Gly Glu Pro Gly Leu Pro Gly Ala Arg Gly Leu Thr Gly Arg 485 490 495 Pro Gly Asp Ala Gly Pro Gln Gly Lys Val Gly Pro Ser Gly Ala Pro 500 505 510 Gly Glu Asp Gly Arg Pro Gly Pro Pro Gly Pro Gln Gly Ala Arg Gly 515 520 525 Gln Pro Gly Val Met Gly Phe Pro Gly Pro Lys Gly Ala Asn Gly Glu 530 535 540 Pro Gly Lys Ala Gly Glu Lys Gly Leu Pro Gly Ala Pro Gly Leu Arg 545 550 555 560 Gly Leu Pro Gly Lys Asp Gly Glu Thr Gly Ala Glu Gly Pro Pro Gly 565 570 575 Pro Ala Gly Pro Ala Gly Glu Arg Gly Glu Gln Gly Ala Pro Gly Pro 580 585 590 Ser Gly Phe Gln Gly Leu Pro Gly Pro Pro Gly Pro Pro Gly Glu Gly 595 600 605 Gly Lys Pro Gly Asp Gln Gly Val Pro Gly Glu Ala Gly Ala Pro Gly 610 615 620 Leu Val Gly Pro Arg Gly Glu Arg Gly Phe Pro Gly Glu Arg Gly Ser 625 630 635 640 Pro Gly Ala Gln Gly Leu Gln Gly Pro Arg Gly Leu Pro Gly Thr Pro 645 650 655 Gly Thr Asp Gly Pro Lys Gly Ala Ser Gly Pro Ala Gly Pro Pro Gly 660 665 670 Ala Gln Gly Pro Pro Gly Leu Gln Gly Met Pro Gly Glu Arg Gly Ala 675 680 685 Ala Gly Ile Ala Gly Pro Lys Gly Asp Arg Gly Asp Val Gly Glu Lys 690 695 700 Gly Pro Glu Gly Ala Pro Gly Lys Asp Gly Gly Arg Gly Leu Thr Gly 705 710 715 720 Pro Ile Gly Pro Pro Gly Pro Ala Gly Ala Asn Gly Glu Lys Gly Glu 725 730 735 Val Gly Pro Pro Gly Pro Ala Gly Ser Ala Gly Ala Arg Gly Ala Pro 740 745 750 Gly Glu Arg Gly Glu Thr Gly Pro Pro Gly Thr Ser Gly Ile Ala Gly 755 760 765 Pro Pro Gly Ala Asp Gly Gln Pro Gly Ala Lys Gly Glu Gln Gly Glu 770 775 780 Ala Gly Gln Lys Gly Asp Ala Gly Ala Pro Gly Pro Gln Gly Pro Ser 785 790 795 800 Gly Ala Pro Gly Pro Gln Gly Pro Thr Gly Val Thr Gly Pro Lys Gly 805 810 815 Ala Arg Gly Ala Gln Gly Pro Pro Gly Ala Thr Gly Phe Pro Gly Ala 820 825 830 Ala Gly Arg Val Gly Pro Pro Gly Ser Asn Gly Asn Pro Gly Pro Pro 835 840 845 Gly Pro Pro Gly Pro Ser Gly Lys Asp Gly Pro Lys Gly Ala Arg Gly 850 855 860 Asp Ser Gly Pro Pro Gly Arg Ala Gly Glu Pro Gly Leu Gln Gly Pro 865 870 875 880 Ala Gly Pro Pro Gly Glu Lys Gly Glu Pro Gly Asp Asp Gly Pro Ser 885 890 895 Gly Ala Glu Gly Pro Pro Gly Pro Gln Gly Leu Ala Gly Gln Arg Gly 900 905 910 Ile Val Gly Leu Pro Gly Gln Arg Gly Glu Arg Gly Phe Pro Gly Leu 915 920 925 Pro Gly Pro Ser Gly Glu Pro Gly Gln Gln Gly Ala Pro Gly Ala Ser 930 935 940 Gly Asp Arg Gly Pro Pro Gly Pro Val Gly Pro Pro Gly Leu Thr Gly 945 950 955 960 Pro Ala Gly Glu Pro Gly Arg Glu Gly Ser Pro Gly Ala Asp Gly Pro 965 970 975 Pro Gly Arg Asp Gly Ala Ala Gly Val Lys Gly Asp Arg Gly Glu Thr 980 985 990 Gly Ala Val Gly Ala Pro Gly Ala Pro Gly Pro Pro Gly Ser Pro Gly 995 1000 1005 Pro Ala Gly Pro Thr Gly Lys Gln Gly Asp Arg Gly Glu Ala Gly Ala 1010 1015 1020 Gln Gly Pro Met Gly Pro Ser Gly Pro Ala Gly Ala Arg Gly Ile Gln 1025 1030 1035 1040 Gly Pro Gln Gly Pro Arg Gly Asp Lys Gly Glu Ala Gly Glu Pro Gly 1045 1050 1055 Glu Arg Gly Leu Lys Gly His Arg Gly Phe Thr Gly Leu Gln Gly Leu 1060 1065 1070 Pro Gly Pro Pro Gly Pro Ser Gly Asp Gln Gly Ala Ser Gly Pro Ala 1075 1080 1085 Gly Pro Ser Gly Pro Arg Gly Pro Pro Gly Pro Val Gly Pro Ser Gly 1090 1095 1100 Lys Asp Gly Ala Asn Gly Ile Pro Gly Pro Ile Gly Pro Pro Gly Pro 1105 1110 1115 1120 Arg Gly Arg Ser Gly Glu Thr Gly Pro Ala Gly Pro Pro Gly Asn Pro 1125 1130 1135 Gly Pro Pro Gly Pro Pro Gly Pro Pro Gly Pro Gly Ile Asp Met Ser 1140 1145 1150 Ala Phe Ala Gly Leu Gly Pro Arg Glu Lys Gly Pro Asp Pro Leu Gln 1155 1160 1165 Tyr Met Arg Ala Asp Gln Ala Ala Gly Gly Leu Arg Gln His Asp Ala 1170 1175 1180 Glu Val Asp Ala Thr Leu Lys Ser Leu Asn Asn Gln Ile Glu Ser Ile 1185 1190 1195 1200 Arg Ser Pro Glu Gly Ser Arg Lys Asn Pro Ala Arg Thr Cys Arg Asp 1205 1210 1215 Leu Lys Leu Cys His Pro Glu Trp Lys Ser Gly Asp Tyr Trp Ile Asp 1220 1225 1230 Pro Asn Gln Gly Cys Thr Leu Asp Ala Met Lys Val Phe Cys Asn Met 1235 1240 1245 Glu Thr Gly Glu Thr Cys Val Tyr Pro Asn Pro Ala Asn Val Pro Lys 1250 1255 1260 Lys Asn Trp Trp Ser Ser Lys Ser Lys Glu Lys Lys His Ile Trp Phe 1265 1270 1275 1280 Gly Glu Thr Ile Asn Gly Gly Phe His Phe Ser Tyr Gly Asp Asp Asn 1285 1290 1295 Leu Ala Pro Asn Thr Ala Asn Val Gln Met Thr Phe Leu Arg Leu Leu 1300 1305 1310 Ser Thr Glu Gly Ser Gln Asn Ile Thr Tyr His Cys Lys Asn Ser Ile 1315 1320 1325 Ala Tyr Leu Asp Glu Ala Ala Gly Asn Leu Lys Lys Ala Leu Leu Ile 1330 1335 1340 Gln Gly Ser Asn Asp Val Glu Ile Arg Ala Glu Gly Asn Ser Arg Phe 1345 1350 1355 1360 Thr Tyr Thr Ala Leu Lys Asp Gly Cys Thr Lys His Thr Gly Lys Trp 1365 1370 1375 Gly Lys Thr Val Ile Glu Tyr Arg Ser Gln Lys Thr Ser Arg Leu Pro 1380 1385 1390 Ile Ile Asp Ile Ala Pro Met Asp Ile Gly Gly Pro Glu Gln Glu Phe 1395 1400 1405 Gly Val Asp Ile Gly Pro Val Cys Phe Leu 1410 1415 1078 amino acids amino acid linear protein Homo sapiens COLLAGEN ALPHA 1 (III) 21 Gln Asn Tyr Ser Pro Gln Tyr Asp Ser Tyr Asp Val Lys Ser Gly Gly 1 5 10 15 Val Ala Val Gly Gly Leu Ala Gly Tyr Pro Gly Pro Ala Gly Pro Pro 20 25 30 Gly Pro Pro Gly Pro Pro Gly Thr Ser Gly His Pro Gly Ser Pro Gly 35 40 45 Ser Pro Gly Tyr Gln Gly Pro Pro Gly Glu Pro Gly Gln Ala Gly Pro 50 55 60 Ser Gly Pro Pro Gly Pro Pro Gly Ala Ile Gly Pro Ser Gly Pro Ala 65 70 75 80 Gly Lys Asp Gly Glu Ser Gly Arg Pro Gly Arg Pro Gly Asp Arg Gly 85 90 95 Leu Pro Gly Pro Pro Gly Ile Lys Gly Pro Ala Gly Ile Pro Gly Phe 100 105 110 Pro Gly Met Lys Gly His Arg Gly Phe Asp Gly Arg Asn Gly Glu Lys 115 120 125 Gly Glu Thr Gly Ala Pro Gly Leu Lys Gly Glu Asn Gly Leu Pro Gly 130 135 140 Glu Asn Gly Ala Pro Gly Pro Met Gly Pro Arg Gly Ala Pro Gly Glu 145 150 155 160 Arg Gly Arg Pro Gly Leu Pro Gly Ala Ala Gly Ala Arg Gly Asn Asp 165 170 175 Gly Ala Arg Gly Ser Asp Gly Gln Pro Gly Pro Pro Gly Pro Pro Gly 180 185 190 Thr Ala Gly Phe Pro Gly Ser Pro Gly Ala Lys Gly Glu Val Gly Pro 195 200 205 Ala Gly Ser Pro Gly Ser Asn Gly Ala Pro Gly Gln Arg Gly Glu Pro 210 215 220 Gly Pro Gln Gly His Ala Gly Ala Gln Gly Pro Pro Gly Pro Pro Gly 225 230 235 240 Ile Asn Gly Ser Pro Gly Gly Lys Gly Glu Met Gly Pro Ala Gly Ile 245 250 255 Pro Gly Ala Pro Gly Leu Met Gly Ala Arg Gly Pro Pro Gly Pro Ala 260 265 270 Gly Ala Asn Gly Ala Pro Gly Leu Arg Gly Gly Ala Gly Glu Pro Gly 275 280 285 Lys Asn Gly Ala Lys Gly Glu Pro Gly Pro Arg Gly Glu Arg Gly Glu 290 295 300 Ala Gly Ile Pro Gly Val Pro Gly Ala Lys Gly Glu Asp Gly Lys Asp 305 310 315 320 Gly Ser Pro Gly Asp Pro Gly Ala Asn Gly Leu Pro Gly Ala Ala Gly 325 330 335 Glu Arg Gly Ala Leu Gly Ser Arg Gly Pro Ala Gly Pro Asn Gly Ile 340 345 350 Pro Gly Glu Lys Gly Pro Ala Gly Glu Arg Gly Ala Pro Gly Pro Ala 355 360 365 Gly Pro Arg Gly Ala Ala Gly Glu Pro Gly Arg Asp Gly Val Pro Gly 370 375 380 Gly Pro Gly Met Arg Gly Met Pro Gly Ser Pro Gly Gly Pro Gly Ser 385 390 395 400 Asp Gly Lys Pro Gly Pro Pro Gly Ser Gln Gly Glu Ser Gly Arg Pro 405 410 415 Gly Pro Pro Gly Pro Ser Gly Pro Arg Gly Gln Pro Gly Val Met Gly 420 425 430 Phe Pro Gly Pro Lys Gly Asn Asp Gly Ala Pro Gly Lys Asn Gly Glu 435 440 445 Arg Gly Gly Pro Gly Gly Pro Gly Pro Gln Gly Pro Pro Gly Lys Asn 450 455 460 Gly Glu Tyr Gly Pro Gln Gly Pro Pro Gly Pro Thr Gly Pro Gly Gly 465 470 475 480 Asp Lys Gly Asp Thr Gly Pro Arg Gly Pro Gln Gly Leu Gln Gly Leu 485 490 495 Pro Gly Thr Gly Gly Pro Pro Gly Glu Asn Glu Lys Pro Gly Glu Pro 500 505 510 Gly Pro Lys Gly Glu Ala Gly Ala Pro Gly Ala Pro Gly Gly Lys Gly 515 520 525 Asp Ala Gly Ala Pro Gly Glu Arg Gly Pro Pro Gly Leu Ala Gly Ala 530 535 540 Pro Gly Leu Arg Gly Gly Ala Gly Pro Pro Gly Pro Glu Gly Gly Lys 545 550 555 560 Gly Ala Ala Gly Pro Pro Gly Pro Pro Gly Ala Ala Gly Thr Pro Gly 565 570 575 Leu Gln Gly Met Pro Gly Glu Arg Gly Gly Leu Gly Ser Pro Gly Pro 580 585 590 Lys Gly Asp Lys Gly Glu Pro Gly Gly Pro Gly Ala Asp Gly Val Pro 595 600 605 Gly Lys Asp Gly Pro Arg Gly Pro Thr Gly Pro Ile Gly Pro Pro Gly 610 615 620 Pro Ala Gly Gln Pro Gly Asp Lys Gly Glu Gly Gly Ala Pro Gly Leu 625 630 635 640 Pro Gly Ile Ala Gly Pro Arg Gly Ser Pro Gly Glu Arg Gly Glu Thr 645 650 655 Gly Pro Pro Gly Pro Ala Gly Phe Pro Gly Ala Pro Gly Gln Asn Gly 660 665 670 Glu Pro Gly Gly Lys Gly Glu Arg Gly Ala Pro Gly Glu Lys Gly Glu 675 680 685 Gly Gly Pro Pro Gly Val Ala Val Pro Pro Gly Gly Ser Gly Pro Ala 690 695 700 Gly Pro Pro Gly Pro Gln Gly Val Lys Gly Glu Arg Gly Ser Pro Gly 705 710 715 720 Gly Pro Gly Ala Ala Gly Phe Pro Gly Ala Arg Gly Leu Pro Gly Pro 725 730 735 Pro Gly Ser Asn Gly Asn Pro Gly Pro Pro Gly Pro Ser Gly Ser Pro 740 745 750 Gly Lys Asp Gly Pro Pro Gly Pro Ala Gly Asn Thr Gly Ala Pro Gly 755 760 765 Ser Pro Gly Val Ser Gly Pro Lys Gly Asp Ala Gly Gln Pro Gly Glu 770 775 780 Lys Gly Ser Pro Gly Ala Gln Gly Pro Pro Gly Ala Pro Gly Pro Leu 785 790 795 800 Gly Ile Ala Gly Ile Thr Gly Ala Arg Gly Leu Ala Gly Pro Pro Gly 805 810 815 Met Pro Gly Pro Arg Gly Ser Pro Gly Pro Gln Gly Val Lys Gly Glu 820 825 830 Ser Gly Lys Pro Gly Ala Asn Gly Leu Ser Gly Glu Arg Gly Pro Pro 835 840 845 Gly Pro Gln Gly Leu Pro Gly Leu Ala Gly Thr Ala Gly Glu Pro Gly 850 855 860 Arg Asp Gly Asn Pro Gly Ser Asp Gly Leu Pro Gly Arg Asp Gly Ser 865 870 875 880 Pro Gly Gly Lys Gly Asp Arg Gly Glu Asn Gly Ser Pro Gly Ala Pro 885 890 895 Gly Ala Pro Gly His Pro Gly Pro Pro Gly Pro Val Gly Pro Ala Gly 900 905 910 Lys Ser Gly Asp Arg Gly Glu Ser Gly Pro Ala Gly Pro Ala Gly Ala 915 920 925 Pro Gly Pro Ala Gly Ser Arg Gly Ala Pro Gly Pro Gln Gly Pro Arg 930 935 940 Gly Asp Lys Gly Glu Thr Gly Glu Arg Gly Ala Ala Gly Ile Lys Gly 945 950 955 960 His Arg Gly Phe Pro Gly Asn Pro Gly Ala Pro Gly Ser Pro Gly Pro 965 970 975 Ala Gly Gln Gln Gly Ala Ile Gly Ser Pro Gly Pro Ala Gly Pro Arg 980 985 990 Gly Pro Val Gly Pro Ser Gly Pro Pro Gly Lys Asp Gly Thr Ser Gly 995 1000 1005 His Pro Gly Pro Ile Gly Pro Pro Gly Pro Arg Gly Asn Arg Gly Glu 1010 1015 1020 Arg Gly Ser Glu Gly Ser Pro Gly His Pro Gly Gln Ser Gly Pro Pro 1025 1030 1035 1040 Gly Pro Pro Gly Ala Pro Gly Pro Cys Cys Gly Gly Val Gly Ala Pro 1045 1050 1055 Ala Ile Ala Gly Ile Gly Ala Glu Lys Ala Gly Gly Phe Ala Pro Tyr 1060 1065 1070 Tyr Gly Asp Glu Pro Met 1075 

What is claimed is:
 1. A peptide synthesized to match an α1(I) or α2(I) telopeptide component of a cross-linked telopeptide degradation product of type I collagen selected from among Asp-Glu-Lys-Ser-Thr-Gly-Gly (SEQ. ID NO: 1), Gln-Tyr-Asp-Gly-Lys-Gly-Val-Gly (SEQ. ID NO: 3), and Glu-Lys-Ala-His-Asp-Gly-Gly-Arg (SEQ. ID NO: 2).
 2. The synthetic peptide of claim 1, consisting of Asp-Glu-Lys-Ser-Thr-Gly-Gly (SEQ. ID NO: 1).
 3. The synthetic peptide of claim 1, consisting of Gln-Tyr-Asp-Gly-Lys-Gly-Val-Gly (SEQ. ID NO: 3).
 4. The synthetic peptide of claim 1, consisting of Glu-Lys-Ala-His-Asp-Gly-Gly-Arg (SEQ. ID NO: 2). 